/// @file
/// @author David Pilger <dpilger26@gmail.com>
/// [GitHub Repository](https://github.com/dpilger26/NumCpp)
///
/// License
/// Copyright 2020 David Pilger
///
/// Permission is hereby granted, free of charge, to any person obtaining a copy of this
/// software and associated documentation files(the "Software"), to deal in the Software
/// without restriction, including without limitation the rights to use, copy, modify,
/// merge, publish, distribute, sublicense, and/or sell copies of the Software, and to
/// permit persons to whom the Software is furnished to do so, subject to the following
/// conditions :
///
/// The above copyright notice and this permission notice shall be included in all copies
/// or substantial portions of the Software.
///
/// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
/// INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
/// PURPOSE AND NONINFRINGEMENT.IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE
/// FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
/// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
/// DEALINGS IN THE SOFTWARE.
///
/// Description
/// Mirror boundary
///
#pragma once

#include "NumCpp/Core/Internal/StaticAsserts.hpp"
#include "NumCpp/Core/Shape.hpp"
#include "NumCpp/Core/Slice.hpp"
#include "NumCpp/Core/Types.hpp"
#include "NumCpp/Functions/flipud.hpp"
#include "NumCpp/NdArray.hpp"

namespace nc
{
    namespace filter
    {
        namespace boundary
        {
            //============================================================================
            // Method Description:
            ///						Mirror boundary
            ///
            /// @param				inImage
            /// @param              inBoundarySize
            /// @return
            ///				NdArray
            ///
            template<typename dtype>
            NdArray<dtype> mirror2d(const NdArray<dtype>& inImage, uint32 inBoundarySize)
            {
                STATIC_ASSERT_ARITHMETIC(dtype);

                const Shape inShape = inImage.shape();
                Shape outShape(inShape);
                outShape.rows += inBoundarySize * 2;
                outShape.cols += inBoundarySize * 2;

                NdArray<dtype> outArray(outShape);
                outArray.put(Slice(inBoundarySize, inBoundarySize + inShape.rows),
                    Slice(inBoundarySize, inBoundarySize + inShape.cols), inImage);

                for (uint32 row = 0; row < inBoundarySize; ++row)
                {
                    // bottom
                    outArray.put(row,
                        Slice(inBoundarySize, inBoundarySize + inShape.cols),
                        inImage(inBoundarySize - row, Slice(0, inShape.cols)));

                    // top
                    outArray.put(row + inBoundarySize + inShape.rows,
                        Slice(inBoundarySize, inBoundarySize + inShape.cols),
                        inImage(inShape.rows - row - 2, Slice(0, inShape.cols)));
                }

                for (uint32 col = 0; col < inBoundarySize; ++col)
                {
                    // left
                    outArray.put(Slice(inBoundarySize, inBoundarySize + inShape.rows),
                        col,
                        inImage(Slice(0, inShape.rows), inBoundarySize - col));

                    // right
                    outArray.put(Slice(inBoundarySize, inBoundarySize + inShape.rows),
                        col + inBoundarySize + inShape.cols,
                        inImage(Slice(0, inShape.rows), inShape.cols - col - 2));
                }

                // now fill in the corners
                NdArray<dtype> lowerLeft = flipud(outArray(Slice(inBoundarySize + 1, 2 * inBoundarySize + 1),
                    Slice(0, inBoundarySize)));
                NdArray<dtype> lowerRight = flipud(outArray(Slice(inBoundarySize + 1, 2 * inBoundarySize + 1),
                    Slice(outShape.cols - inBoundarySize, outShape.cols)));

                const uint32 upperRowStart = outShape.rows - 2 * inBoundarySize - 1;
                NdArray<dtype> upperLeft = flipud(outArray(Slice(upperRowStart, upperRowStart + inBoundarySize),
                    Slice(0, inBoundarySize)));
                NdArray<dtype> upperRight = flipud(outArray(Slice(upperRowStart, upperRowStart + inBoundarySize),
                    Slice(outShape.cols - inBoundarySize, outShape.cols)));

                outArray.put(Slice(0, inBoundarySize), Slice(0, inBoundarySize), lowerLeft);
                outArray.put(Slice(0, inBoundarySize), Slice(outShape.cols - inBoundarySize, outShape.cols), lowerRight);
                outArray.put(Slice(outShape.rows - inBoundarySize, outShape.rows),
                    Slice(0, inBoundarySize), upperLeft);
                outArray.put(Slice(outShape.rows - inBoundarySize, outShape.rows),
                    Slice(outShape.cols - inBoundarySize, outShape.cols), upperRight);

                return outArray;
            }
        }  // namespace boundary
    } // namespace filter
}  // namespace nc
